Lord's Day in Christianity is generally Sunday, the day of communal worship. It is observed by most Christians as the weekly memorial of the resurrection of Jesus Christ, who is said in the canonical Gospels to have been witnessed alive from the dead early on the first day of the week. (A minority of Christians hold that the term "Lord's Day" can only properly refer to seventh-day Sabbath or Saturday.) The phrase appears in Rev. 1:10.

According to some sources, some professed Christians held corporate worship on Sunday in the 1st century. 2nd century writers such as Justin Martyr attest to the widespread practice of Sunday worship (First Apology, chapter 67), and by 361 AD it had become a mandated weekly occurrence. During the Middle Ages, Sunday worship became associated with Sabbatarian (rest) practices. Some Protestants today (particularly those theologically descended from the Puritans) regard Sunday as Christian Sabbath, a practice known as first-day Sabbatarianism.

Sunday was also known in patristic writings as the eighth day, according to the old nundinal cycle.

Operation Sea Lion (German: Unternehmen Seelöwe) was Germany's plan to invade the United Kingdom during the Second World War, beginning in 1940. To have had any chance of success, however, the operation would have required air and naval supremacy over the English Channel. With the German defeat in the Battle of Britain, Sea Lion was postponed indefinitely on 17 September 1940 and never carried out.

By early November 1939, Adolf Hitler had decided on forcing a decision in the West by invading Belgium, the Netherlands and France. With the prospect of the Channel ports falling under Kriegsmarine (German Navy) control and attempting to anticipate the obvious next step that might entail, Grand Admiral (Großadmiral) Erich Raeder (head of the Kriegsmarine) instructed his operations officer, Kapitän Hans Jürgen Reinicke, to draw up a document examining "the possibility of troop landings in England should the future progress of the war make the problem arise." Reinicke spent five days on this study and set forth the following prerequisites:

Charles "Chuck" Missler is an author, evangelical Christian, Bible teacher, former businessman and US Naval officer. He is the founder of the Koinonia House ministry based in Coeur d'Alene, Idaho.

Missler was for several years the chairman, the chief executive, and the largest shareholder of Western Digital. In 1983 he became the chairman and chief executive of Helionetics Inc., another technology company. After teaching for many years at Calvary Chapel Costa Mesa, Missler moved to Coeur d'Alene in 1992 and founded Koinonia House. Through this organization, Missler distributes a monthly newsletter, Bible study tapes, and a radio show, and speaks at conferences.

Missler is a prominent speaker on the subject of bible prophecy. Missler has had numerous programs aired on the Christian television station GOD TV, namely the DVD versions of his biblical studies "Learn the Bible in 24 Hours", "The Book of Revelation", "The Book of Genesis", and "The Book of Daniel".^{[citation needed]} A Los Angeles Times article reported that Missler and co-author Hal Lindsey had plagiarized a portion of Miami University Professor Edwin Yamauchi's 1982 book Foes From the Northern Frontier in their own 1992 book The Magog Factor. A YouTube video in which Missler uses a jar of peanut butter to attempt to disprove evolution attracted media attention in 2007-2008.